Process for electrolytically depositing elemental chromium upon metals



, Wheeling, in the county of Ohio and Patented Apr. 28, 1925.

SAMUEL PEACOCK, or WHEEIQII'NG, WEST VIRGINIA.

PROCESS FOR ELEGTROLYTICALLY DElPOSITING ELEMENTAL CHROMEIUM UPON METALS.

No Drawing To all whom itma z concern Be it known that. I, SAMUEL PEACOCK, a citizen of the United States, residin attate of West Virginia, have invented certain new and usefulImp-rovements in Processes for Electrolyt-ically Depositing Elemental Chromium Upon Metals; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process for electrolytically depositing elemental chromium upon metals, and has for its object to improve the procedures heretofore. proposed.

With these and other objects in view, the invention consists in the novel steps and combinations of steps constituting the process, all as will be more fully hereinafter disclosed and particularly pointed out in the claims.

In carrying out this invention, I provide a suitable bath from a fused salt of chromium such for example as a bath of an alkali metal chromium fluoride containing a small proportion of basic sodium silicate. By this term, I mean a compound such as Na SiO or any sodium silicate containing sodium oxide exceeding 0 per cent. The concentration of the chromium in the bath is maintained in any suitable manner, as by the addition of finely divided chromic-oxide,

and any suitable mechanical means for thoroughly stirrlng the mixture or incorporating the chromic oxide with the fused-- bath may also be provided 7 The electrodes may be ofany suitable material, the anode being either a soluble chromiurn compound or alloy or it'may be of carbon.

The purpose in hand involves the deposition of the elemental chromium from the above-mentioned .-fuse d salt either for the purpose of making a rust-resisting coating upon metals'that are prone to corrosion under various conditions of contact with corrothe cathodes upon which the chromium has been deposited, and thereby producing. an

alloy of chromium and the melted cathode ,which will be substantially free of metal loids. To illustrate, I deposit chromium upon very pure iron sheets for example, and

the coating process is followed by the fusion through any suitable means, of said sheets,

said coated cathode to a Application filed Kay 10, 1924. Serial No. 712,451.

whereupon a ferro-chromium alloy is made which is substantially free of metalloid impurities. Or, to illustrate the use of this process in the making of a chromium sur- 00 faced object, with veryhigh corrosion re-" Q 'sisting properties, I employ a mild steel Wire materials or salt but it is found to be smooth 4 and'polished, and burnished as well, to the extent desired.

Either a potassium chromium fluoride or a sodium chromium. fluoride may be employed for the bath.

What I claim is:

1. The process of coating a metal with chromium which consists in preparing a fused bath of an alkali metal chromium fluoride; adding to said bath a basic sodium silicate; employing the metal to .be coated as the cathode in said bath, and plating out the chromium present-by 'passing a current from said bath to said cathode.

2. The process of coating a metal with chromium which consists in preparing a fused bath; of an alkali .metal chromium fluoride; adding to said bath a basic sodium silicate; adding to said bath suflicient chro -mic oxide to maintain the concentration of said bath substantially constant; employin the metal to be coated as the cathode in sai bath; and plating out the chromium present by passing a current from said bath to said cathode.

3. The process of coating a metal with chromium which consists in preparing a fused bath of an alkali metal chromium fluoride; adding to said bath a basic sodium silicate; employing the metal to be coated as the cathode in said bath; plating out the chromium present by passinga current from said bath to said cathode; and subjecting wiping and burnishing action. I

4. The procss of coating a metal" with chromium which consists in preparing a fused bath of an alkali metal chromium fluoride; adding to said'bath a basic sodium silicate; employing the metal to be coated 110 as the cathode in said bath; plating out the chromium present by passing a current from said bath to said cathode; and melting said iron free from metalloids as the cathode in coatedcathode to provide an alloy of the latsaid-bath; plating out the chromium to be ter and chromium. alloyed on to said iron; and melting the 10 5. The process of making an alloy of iron chromium coated iron to form the desired I 5 and chromium free from metalloids which alloy.

consists in preparing a fused bath of an al- In testimony whereof I aflix my signature.

kali metal chromium fluoride; employing SAMUEL PEACOCK. 

